The present invention provides heavy duty detergent compositions, particularly for imparting improved softness and detersive effects to fabrics laundered therewith, said composition including in addition to conventional builder and principally anionic surfactant components, cationic softener of the di-lower-di-higher alkyl quaternary ammonium and/or heterocyclic imide type, e.g. imidazolinium, and a mixture of fatty acid soap, nonionic organic surfactant, and magnesium sulfate, the weight ratio of soap to softener being about 8:1 to 1:3 preferably 5:1 to 1:2, more preferably 3:2:2:3, e.g., about unity. The soap-nonionic surfactant magnesium sulfate mixture is in the form of a spaghetti, flake, or other shape and is present in the product composition as substantially homogeneously dispersed, discrete particles. A process of laundering fabrics using the above-mentioned composition is also disclosed.